JP3983581B2 - Three-dimensional shape generation program and three-dimensional shape generation method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a CAD (Computer Aided Design) system for designing a three-dimensional shape.
[0002]
[Prior art]
In recent years, in order to shorten a design period and improve design quality, a CAD system for designing industrial products, buildings and the like using a computer has been widely used. Many three-dimensional CAD systems employ a method of processing a model in units of shape features (features) such as protrusions and holes. In many cases, the three-dimensional CAD system has a “feature parametric function” that can easily change the shape of the feature by changing a parameter that defines the feature. In many three-dimensional CAD systems having a feature parametric function, a feature is a unit to be created in one drawing, and a unit to be edited such as a subsequent deletion or a change in order in the generation history.
[0003]
[Problems to be solved by the invention]
By the way, in a three-dimensional CAD system having a feature parametric function, for example, when a tap hole (stepped hole) is generated, the shape can be generated by the following three methods. That is, in the first method, a hole with a depth a is created, and a hole with a depth b is created from the bottom surface to generate a tap hole shape. In the second method, half of the longitudinal sectional shape of the tap hole is rotated 360 degrees to generate the shape of the tap hole. In the third method, a dedicated command for generating a tap hole is used.
[0004]
However, such a method has the following problems. That is, in the first method, since the tapped hole is generated by two holes, the tapped hole is composed of two features, and the subsequent editing operation is not easy. In the second method, a vertical cross-sectional view of the tap hole is necessary. When there is only a plan view of the tap hole viewed from directly above, the vertical cross-sectional view has to be newly created. In the third method, since the dedicated command can generate only a predetermined shape, it lacks flexibility. Therefore, the working efficiency related to the generation of the three-dimensional shape is not very good.
[0005]
Therefore, in view of the conventional problems as described above, the present invention can constitute one feature based on a plurality of loops whose outlines do not intersect, and can input an arbitrary extrusion dimension for each loop. By doing in this way, it aims at providing the three-dimensional shape production | generation technique which improved the working efficiency which concerns on a three-dimensional shape production | generation.
[0006]
[Means for Solving the Problems]
For this reason, in the three-dimensional shape generation technique according to the present invention, a cross section consisting of a plurality of loops whose outlines do not intersect is created, and arbitrary dimensions for extruding each loop in a predetermined direction are input and input. Based on the measured dimensions, each loop is extruded in a predetermined direction to generate a three-dimensional shape. At this time, it is desirable that the cross section is composed of various primitives for adding one feature with the basic feature as a base.
[0007]
According to such a configuration, arbitrary dimensions for extruding in a predetermined direction are input to each of the loops whose outlines do not intersect among various primitives constituting a cross section for adding one feature. Then, based on the input dimensions, each loop is pushed out in a predetermined direction to generate a three-dimensional shape. For this reason, a cross section is created by a plurality of loops whose outlines do not intersect, and one feature is created based on this, and in editing operations such as deleting features or changing the order in the generation history, Easy selection of editing target . In addition, since the longitudinal section is not used to generate the feature, the labor required for creating the longitudinal section becomes unnecessary. Furthermore, by inputting different dimensions for each loop constituting the same in the common cross section, it is possible to generate completely different features, and it is not necessary to switch the dedicated commands one by one to create different features. Therefore, it is possible to improve the work efficiency related to the generation of the three-dimensional shape.
[0008]
At this time, if each loop constituting the cross section is notified to the operator, it can be recognized that the dimension can be input, and the working efficiency can be further improved.
In addition, when one loop is included in the other loop and dimensions are specified for each loop, the specified characteristics are judged to determine how to connect the multiple loops into a three-dimensional shape. It is desirable to do. Specifically, when one loop is included in the other loop and both the extrusion amounts of the two loops are set to 0, a loft process for connecting the outlines of the two loops is executed. Is desirable.
[0009]
According to such a configuration, when one loop is included in the other loop and dimensions are designated for each loop, a plurality of loops are connected in accordance with the designated characteristics, and various three-dimensional shapes are connected. Is generated. In particular, when one loop is included in the other loop and both the extrusion amounts of the two loops are set to 0, a tapered portion can be easily generated as a feature by executing loft processing. can do.
[0010]
Furthermore, it is desirable to input the extrusion start position with respect to the reference surface and the extrusion amount for the dimension of the loop. In this way, the feature can be easily and flexibly changed by arbitrarily setting the extrusion start position and the extrusion amount of the loop.
In addition, it is desirable that a plurality of dimensions can be input for the same loop. In this way, for example, a feature having a plurality of features such as countersinks can be easily generated.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 shows a configuration of a three-dimensional shape generation apparatus embodying the present invention.
The three-dimensional shape generation apparatus 10 includes a computer having at least a central processing unit (CPU) and a memory, and various functions for generating a three-dimensional shape are realized by a program loaded in the memory. The three-dimensional shape generation apparatus 10 includes a sectional view creation unit 12, a feature management unit 14, a loop management unit 16, a dimension input unit 18, and a three-dimensional shape generation unit 20.
[0012]
The sectional view creation unit 12 creates a sectional view composed of various primitives for adding one feature such as a protrusion or a hole, using a feature (hereinafter referred to as “basic feature”) as a base of the model as a base. In the feature management unit 14, the sectional view created by the sectional view creation unit 12 and the features configured by the sectional view are managed. In the loop management unit 16, the loops constituting the cross-sectional view are managed by the management table 16A in which the dimensions of the loops constituting the cross-sectional view are set, and the loop search unit 16B that searches a plurality of loops constituting the cross-sectional view. Is done. Here, “loop” refers to primitives whose outlines do not intersect, and one feature is configured based on the primitives. The loop search unit 16B also has a function of notifying an operator (designer) of the searched loop. In the dimension input unit 18, a dimension for generating a three-dimensional shape by pushing out each loop searched by the loop search unit 16B in a predetermined direction is input. In the three-dimensional shape generation unit 20, each loop constituting the cross-sectional view is pushed out in a predetermined direction based on the dimension input by the dimension input unit 18 to generate a three-dimensional shape.
[0013]
The cross-section creation unit 12, the loop search unit 16B, the dimension input unit 18, and the three-dimensional shape generation unit 20 respectively provide a cross-section creation function and a cross-section creation means, a loop notification function, a dimension input function and a dimension input means, In addition, the three-dimensional shape generation function and the three-dimensional shape generation means are realized by software.
Next, the operation of the three-dimensional shape generation apparatus 10 will be described.
[0014]
When generating a three-dimensional shape, first, as shown in FIG. 2A, an “addition plane” for adding a feature to a basic feature is designated. After the designation of the additional surface, as shown in FIG. 5B, various primitives for adding one feature to a cross section that refers to the additional surface in two dimensions are created. In the following description, it is assumed that a truncated cone-shaped hole (hereinafter referred to as “the truncated cone hole”) is added to the additional surface. Next, as shown in FIG. 3C, a great circle A and a small circle B arranged concentrically with respect to the additional surface are created. Here, a series of processes shown in FIGS. 4A to 4C are performed by a drawing function provided from the cross-sectional view creation unit 12.
[0015]
When the creation of the cross-sectional view is completed, the great circle A and the small circle B as the loop constituting the cross section are searched by the loop search function provided from the loop search unit 16B. It is desirable to notify the operator of the searched loop by, for example, changing the display color on the screen or displaying a pop-up window for prompting dimension input. Then, by the dimension input function provided from the dimension input unit 18, as shown in FIG. 4D, arbitrary dimensions are input to each searched loop. In addition, as a dimension, you may employ | adopt either the absolute dimension on the basis of an additional surface, or the relative dimension on the basis of another surface.
[0016]
When the dimension input for each loop is completed, each loop is pushed out in a predetermined direction by the three-dimensional shape generation function provided from the three-dimensional shape generation unit 20. Then, as shown in FIG. 5E, a three-dimensional shape in which the feature is added to the basic feature is generated and displayed on the screen.
Next, the principle of generating a three-dimensional shape will be described using specific examples.
[0017]
FIG. 3 shows the principle of adding two holes having different depths to the additional surface as a first example. On the additional surface, a great circle A and a small circle B constituting one feature are created as shown in FIG. Then, when the dimensions of the large circle A are pushed out by a with respect to the additional surface while the dimensions of the small circle B are pushed out by b with respect to the additional surface, the management as shown in FIG. A table is created. Here, the extrusion start position (item numbers 1 and 3) and the extrusion amount (item numbers 2 and 4) of each loop are set in the management table. When the management table is created, a three-dimensional shape as shown in FIG.
[0018]
FIG. 4 shows the principle of adding a tapped hole (stepped hole) to the additional surface as a second case. On the additional surface, as shown in FIG. 3A, a concentric large circle A and small circle B that constitute one feature are created. When the dimensions of the large circle A are pushed out by a with respect to the additional surface, while the dimensions of the small circle B are pushed out by b with reference to the absolute dimension a (the bottom surface of the large hole), the figure (B A management table as shown in FIG. When the management table is created, a three-dimensional shape as shown in FIG.
[0019]
FIG. 5 shows the principle of adding a truncated conical hole to the additional surface as a third example. On the additional surface, a great circle A and a small circle B shown in FIG. Then, when the dimensions of the large circle A are pushed out by 0 with respect to the additional surface and the small circle B is pushed out by 0 with respect to the absolute dimension b, as shown in FIG. A management table is created. Here, only the extrusion start position of each loop is set in the management table. In other words, in the third case, the extrusion amount of each loop is 0, so omitting this makes it possible to reduce the size of the management table. When the management table is created, a three-dimensional shape as shown in FIG. At this time, both the large circle A and the small circle B have an extrusion amount of 0, so the loft processing is executed so as to connect the outlines of both.
[0020]
FIG. 6 shows the principle of adding a countersink to the additional surface as a fourth example. On the additional surface, a great circle A and a small circle B shown in FIG. The large circle A is pushed out by 0 with respect to the additional surface, while the small circle B is pushed out by 0 with respect to the absolute dimension a, and the dimension is pushed out by b with respect to the absolute dimension a. Then, a management table as shown in FIG. That is, the small circle B is treated as having a plurality of loops B (1) and B (2), and an arbitrary dimension can be input to each of the loops B (1) and B (2). When the management table is created, a three-dimensional shape as shown in FIG. At this time, since both the large circle A and the small circle B (loop B (1)) have an extrusion amount of 0, the loft processing is executed so as to connect the outlines of the two and the small circle B ( The loop B (2)) is extruded by b with respect to the absolute dimension b, and a countersink is generated.
[0021]
Therefore, in the second case to the fourth case, completely different features can be generated by inputting different dimensions for each loop constituting the same in the common cross section. For this reason, it is not necessary to create different features by switching dedicated commands one by one as in the prior art, and the number of operations required to generate a three-dimensional shape can be reduced. In addition, as in the fourth example, a feature having a plurality of features can be easily generated.
[0022]
In each case, since the great circle A and the small circle B constitute one feature, it is easy to select an editing target in an editing operation such as subsequent deletion or order change in the generation history. Further, since each case does not use a cross-sectional view for generating a feature, the labor required for creating the cross-sectional view is not required.
In the above description, a circle as a loop is created on the additional surface. However, as shown in FIG. 7, a loop composed of a rectangle, a pentagon, or other shapes may be created. Moreover, although the example which created the hole in the basic feature is shown as an example, a protrusion can also be created. Such a three-dimensional figure can be created by performing a calculation such as union or intersection with a plurality of features as is well known. Of course, the basic feature is not always necessary, and a two-dimensionally drawn cross-sectional shape obtained by extruding the three-dimensional shape may be used as it is.
[0023]
If a program that realizes such a function is recorded on a computer-readable recording medium such as a CD-ROM or DVD-ROM, the three-dimensional shape generation program according to the present invention can be distributed to the market. it can. A person who has obtained such a recording medium can easily construct a three-dimensional shape generation apparatus according to the present invention using a general computer system.
[0024]
(Supplementary note 1) A cross-section creation function for creating a cross-section composed of a plurality of loops whose outlines do not intersect, a dimension input function for inputting an arbitrary dimension for extruding each loop in a predetermined direction, and the dimensions A three-dimensional shape generation program for causing a computer to realize a three-dimensional shape generation function for generating a three-dimensional shape by pushing out each loop in a predetermined direction based on a dimension input by an input function.
[0025]
(Supplementary note 2) The three-dimensional shape generation program according to supplementary note 1, wherein the cross section includes various primitives for adding one feature with a basic feature as a base.
[0026]
(Supplementary note 3) The three-dimensional shape according to supplementary note 1, further comprising a loop notification function for retrieving a cross section created by the cross section creation function and notifying an operator of each loop constituting the cross section. Generation program.
[0027]
(Supplementary Note 4) The three-dimensional shape generation function is configured such that when one loop is inwardly inserted into the other loop and a dimension is designated for each of the loops, the designated feature is determined, and a plurality of loops are determined. The three-dimensional shape generation program according to any one of Supplementary Note 1 to Supplementary Note 3, which has a function of determining whether to make a three-dimensional connection.
[0028]
(Additional remark 5) The said dimension input function inputs the extrusion start position of the loop with respect to a reference plane, and its extrusion amount, The three-dimensional shape generation program of Additional remark 2 characterized by the above-mentioned.
[0029]
(Appendix 6) The three-dimensional shape generation function connects the outer lines of two loops when one loop is included in the other loop and the extrusion amounts of the two loops are both set to 0. The three-dimensional shape generation program according to appendix 4 or appendix 5, wherein loft processing is executed.
[0030]
(Supplementary note 7) The three-dimensional shape generation program according to supplementary note 1, wherein the dimension input function is capable of inputting a plurality of dimensions to the same loop.
[0031]
(Supplementary note 8) Create a cross-section consisting of a plurality of loops whose outlines do not intersect, input arbitrary dimensions for extruding each loop in a predetermined direction, and based on the input dimensions, each loop A three-dimensional shape generation method characterized in that a three-dimensional shape is generated by extruding in a predetermined direction.
[0032]
(Supplementary note 9) Cross-section creating means for creating a cross section composed of a plurality of loops whose outlines do not intersect with each other, dimension input means for inputting arbitrary dimensions for extruding each loop in a predetermined direction, and the dimensions A three-dimensional shape generation apparatus comprising: three-dimensional shape generation means for generating a three-dimensional shape by pushing out each loop in a predetermined direction based on a dimension input by an input means.
[0033]
(Additional remark 10) The cross-section creation function which creates the cross section which consists of a plurality of loops whose outlines do not intersect, the dimension input function which inputs each arbitrary dimension for pushing out in the predetermined direction about each loop, and the dimensions A computer-readable recording of a 3D shape generation program for causing a computer to realize a 3D shape generation function for generating a 3D shape by pushing out each loop in a predetermined direction based on the dimensions input by the input function. Recording medium.
[0034]
【The invention's effect】
As described above, according to the three-dimensional shape generation technique according to the present invention, a cross section is created by a plurality of loops whose outlines do not intersect with each other, and one feature is configured based on the cross section. Editing operations, such as deleting and changing the order on the generation history, are facilitated. Moreover, since a longitudinal section is not required when generating a feature, the labor required for creating the longitudinal section is not required. Further, by inputting different dimensions for each loop constituting the common cross section, completely different features can be generated. For this reason, it is not necessary to create different features by switching dedicated commands one by one, and the number of operations required to generate a three-dimensional shape can be reduced. Therefore, it is possible to improve the work efficiency related to the generation of the three-dimensional shape.
[Brief description of the drawings]
FIG. 1 is a block diagram of a three-dimensional shape generation apparatus embodying the present invention. FIG. 2 shows a three-dimensional shape generation procedure in the same as above, and (A) to (E) are the first to fifth steps, respectively. FIG. 3 shows a first example of the principle of generating a three-dimensional shape, (A) is an explanatory diagram of a cross section, (B) is an explanatory diagram of a management table, and (C) is an explanation of a generated three-dimensional shape. FIG. 4 shows a second example of the principle of generating a three-dimensional shape, (A) is an explanatory diagram of a cross section, (B) is an explanatory diagram of a management table, and (C) is an explanatory diagram of a generated three-dimensional shape FIG. 5 shows a third example of the principle of generating a three-dimensional shape, (A) is an explanatory diagram of a cross section, (B) is an explanatory diagram of a management table, and (C) is an explanatory diagram of a generated three-dimensional shape. FIG. 6 shows a fourth example of the principle of generating a three-dimensional shape, (A) is an explanatory diagram of a cross section, (B) is an explanatory diagram of a management table, and (C) is generated. Shows another primitive constituting the illustration FIG. 7 is a cross-sectional three-dimensional shape, (A) ~ (C) are explanatory views each first to third examples EXPLANATION OF REFERENCE NUMERALS
DESCRIPTION OF SYMBOLS 10 3D shape production | generation apparatus 12 Sectional drawing preparation part 16B Loop search part 18 Dimension input part 20 3D shape production | generation part

Claims (5)

A cross-section creation function for creating a cross-section consisting of a plurality of loops in which the outer lines do not intersect and one loop is included in the other loop ;
For each of the loops, as a dimension for extruding in a predetermined direction, a dimension input function for inputting an extrusion start position with respect to the reference surface and its extrusion amount , respectively,
Judging the characteristics of the extrusion start position and the amount of extrusion input by the dimension input function, it is determined how to connect a plurality of loops into a three-dimensional shape, and in accordance with the determination, each loop is extruded in a predetermined direction to form a three-dimensional 3D shape generation function to generate shapes,
A three-dimensional shape generation program for realizing a computer.   The three-dimensional shape generation program according to claim 1, further comprising a loop notification function for searching for a cross section created by the cross section creation function and notifying an operator of each loop constituting the cross section. The three-dimensional shape generation program according to claim 1 or 2, wherein the dimension input function can input a plurality of dimensions to the same loop . The three-dimensional shape generation function, when the extrusion amount of the two loops are both set to 0, the claim 1, characterized in that executing the loft process for connecting the outline of the two loops or claim 2 The three-dimensional shape generation program described in 1. Create a cross-section consisting of multiple loops in which the outlines do not intersect and one loop is contained in the other loop ,
For each of the loops, as a dimension for extruding in a predetermined direction, an extrusion start position with respect to the reference surface and its extrusion amount are input,
Judging the characteristics of the input extrusion start position and the amount of extrusion and determining how to connect a plurality of loops to form a three-dimensional shape and extruding each loop in a predetermined direction to generate a three-dimensional shape A three-dimensional shape generation method characterized by

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